1. Field of the Invention
The present invention relates to a simplified record player. More particularly, the invention relates to a simplified construction incorporated in a record player wherein an interrupting switch used for terminating sound reproduction is utilized to appropriately cushion or damp rapid motion and excessive stylus force exerted by a stylus spring at the time when a tone arm is automatically returned to its initial playing point. Due to such simplified construction, any disagreeable harsh noises can be eliminated, and at the same time, spoilage of record grooves, deterioration of the stylus itself, and failures such as poor starting, etc., are completely obviated.
2. Description of the Prior Art
Illustrative of prior art attempts in the field of record players are: the "GAME DEVICE" disclosed in U.S. Pat. No. 2,893,735 issued in 1959 to Tranter, Jr.; the "SIMPLE SOUND REPRODUCING DEVICE" disclosed in U.S. Pat. No. 3,467,393 issued in 1969 to Kuwayama; the "MAGNETICALLY INDEXED SPINNER" disclosed in U.S. Pat. No. 3,492,001 issued in 1970 to Coffey, Sr.; the "PHONOGRAPH TOY HAVING AN IMPROVED SPEAKER CONE" disclosed in U.S. Pat. No. 3,547,448 issued in 1970 to Chang; the "AUDIBLE GAME" disclosed in U.S. Pat. No. 3,779,552 issued in 1973 to Buck; the "SOUND-PRODUCING MIRROR TOY" disclosed in U.S. Pat. No. 4,072,314 issued in 1978 to Rosen et al; the "TOY PHONOGRAPH" disclosed in U.S. Pat. No. 3,672,688 issued in 1972 to Hill; and the "IMPROVED GAME OF CHANCE" disclosed in Australian Pat. Specification No. 164,265 published in 1955. A simplified record player in which a speaker and a sound transfer member are mounted in a casing of the player in a cantilever fashion and the sound transfer member is urged by a spring for imparting a stylus force is well known. A tone arm, when automatically returned to the starting or initial position, acts to urge the movable contact of a switch means so as to move it away from engagement with a fixed contact. Such well known construction is disclosed, for example, in Japanese Laid-Open (Unexamined) Patent Publication No. 105803/1977.
Another type of record player wherein a speaker and a sound transfer member are fixed to a casing and a turntable is able to be moved vertically is also known. A switch is moved to an "ON" or "OFF" position by a vertical motion correlated with the movement of the turntable in the same direction as that of the stylus force. Such type of record player is disclosed in Japanese Patent Publication Nos. 3705/75 and 32271/70. However, record players of this latter type do not provide a tone arm which automatically reverts back to its initial position when playing is terminated, and at such position no adjustment of spring forces of the tone arm and return spring is required. Accordingly, such construction differs essentially from the former type wherein the switch is turned OFF by a force exerted by the return motion of the tone arm.
In the latter type of record player, rotation of the turntable becomes unavoidably slow when the tone arm is situated at a position radially distant from the center of the record, and rotation becomes faster as it approaches the center during playing.
In order to keep the rotational speed of the record disc uniform, at least the sound transfer member must be unfixed, but should be urged by a spring for exerting stylus force, which force becomes larger as the tone arm approaches the center of the record disc.
In view of the foregoing characteristics, a record player of the former type is considered to be preferable to that of the latter type. A simplified record player of this former type is being marketed on a considerably wide scale, however, the following problems therewith remain to be solved:
(1) Because the sound transfer member is carried at its one end in a cantilever fashion and is urged by a stylus force spring, upon return of the tone arm the stylus strongly impinges upon a record disc under a high spring force of the stylus force spring. Thus, it not only generates an unpleasant shock noise but also damages the record disc. PA1 (2) A resilient force exerted by the return spring of the tone arm moves the movable contact against the resilient force of the contact. In this type of device, a return spring should not have a strong resilient force, such that the reproducing stylus is always kept in stable engagement with the record grooves during sound reproduction. Accordingly, in order that the tone arm may be able to move the movable contact by means of the force of its return spring, the spring force of the movable contact must be fairly weak. This naturally gives rise to a very weak contact force between the movable contact and the fixed contact which is likely to be accompanied by frequent variation in the electrical resistance between the two mating contacts, and rotation of the record disc thus becomes irregular. PA1 (3) At the starting point of sound reproduction, when the sound reproduction stylus is positioned at a radially outer part of the record disc, excessive stylus force is often exerted thereon to yield a large moment of force which results in poor starting of the record player. PA1 (4) The tone arm sometimes reverts to the starting point halfway along its course, where the sound transfer member has been scooped up by the cam. When this occurs, the movable contact blade and the fixed contact blade are opposed against each other in the horizontal direction as in the prior art construction, and the tone arm pushes and detaches the movable contact blade from the fixed contact blade so as to interrupt the power supply to the electric motor. In this state, there is the disadvantage that because the sound transfer member is kept halfway on the cam so that no stylus force is imparted to the pickup, the stylus does not engage with the record groove and the tone arm itself cannot move while the start switch is ON. Further, the start switch has to be kept ON until the stylus force is imparted by depressing the sound transfer member by further rotation of the cam. PA1 (5) Because the spring force of the movable contact has been weak, even a slight shock during the playing sometimes causes the contact switch to switch OFF.
The present invention is constructed so as to completely eliminate the above-mentioned drawbacks of the conventional constructions.